<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        td:empty::after{
            content: "/";
        }
        td{text-align: center;}
    </style>
</head>
<body>
    <table border="1" cellspacing="0" width="300px"height="200px">
        <tr>
            <td>hua</td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
        </tr>

 </table>
    
</body>
</html>